C# Crash Course Dimitar Minchev

Transcription

1 C# Crash Course Dimitar Minchev

2 BIO Dimitar Minchev PhD of Informatics, Assistant Professor in Faculty of Computer Science and Engineering, Burgas Free University, Bulgaria. Education Bachelor of Informatics, Burgas Free University, Master of Informatics, Shumen University "Episkop Konstantin Preslavski", PhD of Informatics, Bulgarian Academy of Sciences, The Institute of Information and Communication Technologies, Scientific Interests Computer Science Computer Architectures and Networks Digital Signal Processing

3 Where to start? What you need to start developing C# applications?

4 Technologies This Crash Course is about C#, and it is targeting development using Microsoft technology. Target millions of potential users by choosing Microsoft.

5 Development Environment To Develop Desktop Apps Download: Visual Studio Express 2012 for Desktop To Develop Windows 8 Compatible Apps Download: Visual Studio Express 2012 for Windows 8 To Develop Apps and Games for Windows Phone Download: Visual Studio Express 2012 for Windows Phone

6 Students Benefits DreamSpark is the Newest Microsoft Academic Program that Allows Students to use the Company's Products for Free.

7 C# Basics Let s Start with Introduction to C# Programming Language

8 Storing Integer Values sbyte 8 bits -128 to 127 byte 8 bits 0 to 255 short 16 bits to ushort 16 bits 0 to int 32 bits to uint 32 bits 0 to long 64 bits to ulong 64 bits 0 to char 16 bits 0 to Storing Real Values float 7 digits 1.5E-45 to 3.4E48 double 15 digits 5.0E-324 to 1.7E308 decimal digits

9 Casting We can force C# to regard a value as being of a certain type by the use of casting like this double d = 1.5; float f = (float) d ;

10 Conditional Execution if ( width > 5.0 ) Console.WriteLine ("Too big, use maximum\n") ; width = 5.0 ;

11 Loops for, while, do while for ( SETUP; FINISH_TEST; UPDATE ) // things we want to do a given number of times while (CONDITION) // statement or block do // statement or block while (CONDITION) ;

12 Breaking loops while ( RUNNING_OK ) // complex stuff if ( ABORTED ) break ; // more complex stuff // we are here if aborted becomes true

13 Continuing loops for ( item = 1 ; item < TOTAL_ITEMS ; item=item+1 ) // item processing stuff if ( DONE_ALL_WE_NEED_THIS_TIME ) continue ; // additional item processing stuff...

14 Methods, Parameters, Return value using System ; class ReturnDemo static int sillyreturnplus ( int i) i = i + 1; Console.WriteLine ( "i is : " + i ) ; return i; public static void Main () int res = sillyreturnplus (5); Console.WriteLine ( "result = " + res ) ;

15 Arrays using System; class ArrayDemo public static void Main () int [] scores = new int [11] ; for ( int i=0; i<11; i=i+1) scores [i] = readint ( "Score : ", 0,1000);

16 Multi Dimensional Arrays int [,] board = new int [3,3]; board [1,1] = 1;

17 Exceptions int age; try age = int.parse(agestring); Console.WriteLine("Thank you"); catch (Exception e) // Get the error message out of the exception Console.WriteLine(e.Message);

18 Finally Clause try // Code that might throw an exception catch (Exception outer) // Code that catches the exception finally // Code that is obeyed whether an exception is thrown or not

19 Throwing an Exception throw new Exception( "BOOM );

20 Read TextReader reader = new StreamReader("Test.txt"); string line = reader.readline(); Console.WriteLine (line); reader.close(); Streams Write StreamWriter writer = new StreamWriter("test.txt"); writer.writeline("hello world"); writer.close(); File Path string path; path

21 To Learn Fast Read Books C# Yellow Book by Rob Miles The C# Book is used by the Department of Computer Science in the University of Hull as the Basis of the First Year Programming Course.

22 Console App Windows Making Materials Example

23 Project = Create It Visual C#: Windows Console Application Project name: Windows Making Materials

24 Functionality = The Code Write the code in the Main method

25 Test = Run [F5] Test the Functionality of Your First C# Console App by Run it

26 The Code of the Example // Width Console.Write("Width="); string widthstring = Console.ReadLine(); double width = double.parse(widthstring); // Height Console.Write("Height="); string heightstring = Console.ReadLine(); double height = double.parse(heightstring); // Calcultions double woodlength = 2 * (width + height) * 3.25; double glassarea = 2 * (width * height); // Print Console.WriteLine("The length of the wood is + woodlength + " feet"); Console.WriteLine("The area of the glass is " + glassarea + " square metres"); // Pause Console.ReadKey();

27 C# Classes Everything in C# is in a Class

28 Create Class Classes have members: Constructors Data Members Properties Methods Destructors Members have access modifiers: Public Private Protected

29 class definition start public class Cat private string name; private string color; data member public Cat(string name, string color) this.name = name; this.color = color; constructor public string Name get return this.name; set this.name = value; property

30 property public string Color get return this.color; set this.color = value; get/set property method public void SayMiau() Console.WriteLine("0 cat 1 said: Miau!", color, name); class definition end

31 Use Class Create an instance Initialize its fields Manipulate the instance Read properties Modify properties Invoke methods Release the occupied resources Done automatically in most cases

32 create an instance using default constructor static void Main() Cat Tony = new Cat(); read properties Console.WriteLine("0 cat 1", Tony.Color, Tony.Name ); Tony.Name = "Tony"; Tony.Color = "Green"; Tony.SayMiaw(); modify properties invoke method Cat Pepy = new Cat("Pepy", "White"); Pepy.SayMiaw(); Console.ReadKey(); create an instance using overloaded constructor

33 Console App The Cat Example

34 Project = Create It Visual C#: Windows Console Application Project name: The Cat

35 Functionality = The Code Write the code of the [Cat] class. Save the class in file [Cat.cs] The CS file must have the same name that the CLASS.

36 Test it = Run [F5] Test the Functionality of Your C# Console App by Rin it

37 The Code of the Example public class Cat // data members private string name, color; // properties public string Name get return this.name; set this.name = value; public string Color get return this.color; set this.color = value; // constructor public Cat(string name = Noname", string color = Gray") this.name = name; // method public void SayMiaw() Console.WriteLine("0 cat 1 said: Miaw!", color, name); // start point static void Main() Cat Tony = new Cat(); Console.WriteLine("0 cat 1", Tony.Color, Tony.Name); Tony.Name = "Tony"; Tony.Color = "Green"; Tony.SayMiaw(); Cat Pepy = new Cat("Pepy", "White"); Pepy.SayMiaw(); Console.ReadKey(); this.color = color;

38 Desktop Apps Celsius to Fahrenheit Converter Example

39 Project = Create It Visual C#: Windows Form Application Project name: Celsius to Fahrenheit Converter

40 User Interface = The Form Designer Using the Toolbox Add: Labels, TextBoxes and Buttons Using the Properties: Change the properties of the objects in the form

41 Functionality = The Code Click [Convert] button and write some code Convert from Celsius to Fahrenheit To convert back from Fahrenheit to Celsius use this code instead

42 Test = Run [F5] Test the Functionality of Your First C# Desktop App by Run it

43 The Code of the Example // Celsius to Fahrenheit double C = Convert.ToDouble(textBox1.Text); double F = (C * (9.0 / 5.0)) + 32; textbox2.text = Convert.ToString(F); // Fahrenheit to Celsius double F = Convert.ToDouble(textBox1.Text); double C = (F - 32) * (5.0 / 9.0); textbox2.text = Convert.ToString(C);

44 Store App Syndication Feed Reader Example

45 FeedData.cs // Additional Namespaces using Windows.Web.Syndication; using System.Collections.ObjectModel; namespace RSS // Holds info for a single blog post public class FeedItem public string Title get; set; public string Subtitle get; set; public string Description get; set; public string Image get; set; // Holds a collection of blog feeds (FeedData), and contains methods needed to retreive the feeds. public class FeedDataSource public ObservableCollection<FeedItem> Feeds = new ObservableCollection<FeedItem>(); public async Task GetFeedAsync(string link) SyndicationClient client = new SyndicationClient(); client.bypasscacheonretrieve = true; Uri URI = new Uri(link); SyndicationFeed feed = await client.retrievefeedasync(uri); // This code is executed after RetrieveFeedAsync returns the SyndicationFeed. // Process it and copy the data we want into our FeedData and FeedItem classes. foreach (SyndicationItem item in feed.items) FeedItem SingleItem = new FeedItem(); SingleItem.Title = item.title.text; SingleItem.Subtitle = item.publisheddate.tostring(); SingleItem.Description = item.summary.text; Feeds.Add(SingleItem);

46 MainPage.xaml <Page.Resources> <CollectionViewSource x:name="itemsviewsource" Source="Binding Feeds" /> </Page.Resources> <Grid> <Grid.RowDefinitions> <RowDefinition Height="120"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <GridView x:name="itemgridview" Grid.RowSpan="2" Padding="100" ItemsSource="Binding Source=StaticResource itemsviewsource" ItemTemplate="StaticResource Standard500x130ItemTemplate" /> <Grid> <TextBlock Text="BBC NEWS" Padding=" " Style="StaticResource PageHeaderTextStyle"/> </Grid> </Grid>

47 MainPage.xaml.cs public sealed partial class MainPage : Page private FeedDataSource Data = new FeedDataSource(); private async void LoadContent() List<string> LinkToProcess = new List<string>(); LinkToProcess.Add(" foreach (string Link in LinkToProcess) await Data.GetFeedAsync(Link); foreach (FeedItem feed in Data.Feeds) itemgridview.items.add(feed); // Constructor public MainPage() this.initializecomponent(); LoadContent();

48 Final App Screen

49 Thank You! Send your questions to